在 ggplot2 中用不同的列标记 y 轴

Question

使用 ggplot2，我想创建一个绘图，其中一个变量作为我的 y 轴，但另一个变量作为 y 轴标签

获取这个样本数据：

df <- data_frame(
  YearMonth = c("2018-01", "2018-01", "2018-02", "2018-02", "2018-03", "2018-03", "2018-04", "2018-04", "2018-05", "2018-05", "2018-06", "2018-06", "2019-01", "2019-01", "2019-02", "2019-02", "2019-03", "2019-03", "2019-04", "2019-04", "2019-05", "2019-05", "2019-06", "2019-06"),
  Year = c("2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019"),
  Day = c("1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2"),
  Total = c(11, 43, 12, 81, 90, 74, 8, 3, 7, 14, 50, 99, 67, 45, 31, 23, 46, 53, 4, 90, 34, 46, 98, 2),
)

我可以创建一个平铺图，将“年-月”作为我的 y 轴，“日”作为我的 x 轴，以及“总计”作为我的“填充”值

library(ggplot2)

df %>% 
  ggplot(aes(x = Day,
             y = YearMonth)) + 
  geom_tile(aes(fill = Total),
            colour = "white",
            size = 0.2,
            na.rm = FALSE) + 
  coord_equal(ratio = 1) + 
  scale_fill_gradient2(low = "#F1EDDE", 
                       high = "#C72B26", 
                       midpoint = 10) 

产生以下内容：

但是，我不想将“年月”作为我的 y 轴标签。我想使用“Year”——它只会在左侧垂直轴上产生两个标签（2018 和 2019）

我咨询过similar topics，但没有成功。我尝试使用注释，在 scale_y_discrete 中指定“年份”和辅助轴，但未能达到预期的结果。我将不胜感激有关如何实现这一目标的任何说明

Answer 1

您可以为秤提供明确的中断和标签，或者提供一个函数来获得您想要的结果。下面的代码中的每个示例。我假设你想给一月贴上标签。

library(tidyverse)
#> Warning: package 'tibble' was built under R version 4.0.3
#> Warning: package 'tidyr' was built under R version 4.0.3
#> Warning: package 'dplyr' was built under R version 4.0.3

df <- data.frame(
  YearMonth = c("2018-01", "2018-01", "2018-02", "2018-02", "2018-03", "2018-03", "2018-04", "2018-04", "2018-05", "2018-05", "2018-06", "2018-06", "2019-01", "2019-01", "2019-02", "2019-02", "2019-03", "2019-03", "2019-04", "2019-04", "2019-05", "2019-05", "2019-06", "2019-06"),
  Year = c("2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2018", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019", "2019"),
  Day = c("1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2","1","2"),
  Total = c(11, 43, 12, 81, 90, 74, 8, 3, 7, 14, 50, 99, 67, 45, 31, 23, 46, 53, 4, 90, 34, 46, 98, 2)
)

df %>% 
  ggplot(aes(x = Day,
             y = YearMonth)) + 
  geom_tile(aes(fill = Total),
            colour = "white",
            size = 0.2,
            na.rm = FALSE) + 
  coord_equal(ratio = 1) + 
  scale_fill_gradient2(low = "#F1EDDE", 
                       high = "#C72B26", 
                       midpoint = 10) +
  scale_y_discrete(
    breaks = c("2018-01", "2019-01"),
    labels = c("2018", "2019")
  )

df %>% 
  ggplot(aes(x = Day,
             y = YearMonth)) + 
  geom_tile(aes(fill = Total),
            colour = "white",
            size = 0.2,
            na.rm = FALSE) + 
  coord_equal(ratio = 1) + 
  scale_fill_gradient2(low = "#F1EDDE", 
                       high = "#C72B26", 
                       midpoint = 10) +
  scale_y_discrete(
    breaks = function(x) { x[grepl("-01$", x)] },
    labels = function(x) {data.table::tstrsplit(x, "-")[[1]]}
  )

^{由reprex package (v0.3.0) 于 2020 年 12 月 9 日创建}

Answer 2

你可以试试

df %>% 
  mutate(YearMonth = str_split(YearMonth, "-") %>% map_chr(2) %>% as.numeric) %>%
  mutate(Year = factor(Year, levels = rev(unique(as.numeric(Year))))) %>% 
  ggplot(aes(x = Day,
             y = YearMonth)) + 
  geom_tile(aes(fill = Total),
            colour = "white",
            size = 0.2,
            na.rm = FALSE) + 
  scale_fill_gradient2(low = "#F1EDDE", 
                       high = "#C72B26", 
                       midpoint = 10) +
  coord_equal() +
  facet_wrap(~Year,ncol=1, strip.position = "left") +
  ylab("") +
  theme_bw(base_size = 16) + 
  theme(axis.text.y = element_blank(), 
        axis.ticks.y = element_blank())